Q4 is the practical RAM saver for running local AI models
Running an AI model on a personal computer depends heavily on model size and level. Q4 is the most practical starting point for most individuals.
It can use about half the memory of Q8 while keeping quality close enough for common work such as coding, role play, and . Q8 is mainly worth using when the task needs very precise output, such as careful data where small mistakes can build up.
Q2 may look attractive because it saves more memory, especially when RAM is expensive, but the output becomes clearly worse on tasks that need more than one step. A 7B model at Q4 needs about 4GB, which makes it a good fit for an 8GB machine.
Key points
- Q4 is the best first setting for most personal local AI use.
- Q4 can cut memory use sharply compared with Q8 while keeping similar quality for common tasks.
- Q8 is better for tasks where small output errors can cause bigger problems.
- Q2 saves more memory but hurts quality on multi-step tasks.
- A 7B Q4 model needs about 4GB of memory, so it can fit on many 8GB machines.